And once again, the security advisories (like this one) refer to a new version of Thunderbird, 2.0.0.13 in this case, but that version is not available. The current version, as I write this, is 2.0.0.12. In all fairness, I should add that the vulnerabilities are much less serious in Thunderbird because they are not active in the default configuration. The new, fixed version of SeaMonkey, 1.1.9, is available.